Multiple gear transmission

ABSTRACT

The multiple gear transmission in planetary design comprises one input shaft ( 1 ), one output shaft ( 2 ) which are located in one housing, three single-web planetary sets (P 1,  P 2,  P 3 ) six rotatable shafts ( 1, 2, 3, 4, 5, 6 ), the same as six shifting elements ( 03, 04, 05, 14, 16, 56 ) that include brakes and clutches, the selective engagement of which by pairs produces different reduction ratios between the input shaft ( 1 ) and the output shaft ( 2 ) so that seven forward gears and two reverse gears can be implemented, the input resulting by the shaft ( 1 ) which is directly connected with the sun gear of the first planetary set (P 1 ), the output resulting via one shaft ( 2 ) which is connected with the web of the second planetary set (P 2 ), one shaft ( 3 ) is permanently connected with the sun gear of the second planetary set (P 2 ) and the sun gear of the third planetary set (P 3 ), one shaft ( 4 ) permanently connects the web of the first planetary set (P 1 ) with the ring gear of the third planetary set (P 3 ), one shaft ( 5 ) is permanently connected with the ring gear of the first planetary set (P 1 ), one shaft ( 6 ) permanently connects the web of the third planetary set (P 3 ) with the ring gear of the second planetary set (P 2 ) and the planetary sets (P 1,  P 2,  P 3 ) are coupled with shafts ( 1, 2, 3, 4, 5, 6 ) and shifting elements ( 03, 04, 05, 14, 16, 56 ).

According to the preamble of claim 1 the invention relates to a multiple gear transmission, especially an automatic transmission for a motor vehicle.

Automatic transmissions, especially for motor vehicles, comprise planetary sets shifted by means of frictional or shifting elements, according to the prior art, such as clutches and brakes and usually connected with a starting element like a hydrodynamic torque converter or a fluid clutch subject to slip action and optionally provided with a bridge clutch.

One such transmission results from EP 0 434 525 A1. It essentially comprises one input shaft and one output shaft disposed in parallel, one double planetary gear set situated concentrically to the output shaft and five shifting elements in the form of three clutches and two brakes, the selective locking of which by pairs determines the different gear ratios between the input shaft and the output shaft.

Also known from the Applicant's DE 199 49 507 A1 is a multiple gear transmission where on the input shaft two non-shiftable front-mounted gear sets are provided which produce the output side two rotational speeds which together with the rotational speed of the input shaft can optionally be shifted by selective closing of the shifting elements used to a shiftable double planetary gear set acting upon the output shaft in a manner such that for changing from one gear to the respective higher or lower gear that follows, only one shifting element of the two just actuated shifting elements has to be engaged or disengaged.

There has also been disclosed within the scope of EP 0 434 525 A1 one multiple gear transmission containing one input shaft and one output shaft located in one housing, one planetary set concentric with the output shaft and consisting of four elements designated from one first to one fourth in order of rotational speed, that is, one so-called double planetary set and five shifting elements, namely, three clutches and two brakes, the selective engagement of which by pairs determines different reduction ratios between input shaft and the output shaft, the transmission having two power paths so that by the selective engagement by pairs of the five shifting elements six forward gears are achieved.

DE 199 10 299 C1 has disclosed a planetary gear variable transmission having three transmission elements where one input shaft can be brought to driving connection with one output shaft by at least one of three planetary gear transmission elements. In the known planetary gear variable transmission, by using each time three frictional-engagement clutches and brakes, it is possible to shift five forward gears including one direct gear having a predetermined ratio.

In the known planetary gear variable transmission, it is possible by interrupting a specific driving connection between two of the three transmission elements, to provide an added sixth forward gear. In another embodiment, this is accomplished by additional auxiliary planets and by an added outer auxiliary central gear that meshes with the latter and by an additional brake can be decelerated in the sixth forward gear. In the other embodiments, the auxiliary central gear makes still one seventh forward gear and one additional reverse gear possible.

The problem on which this invention is based is to propose a multiple gear transmission of the kind mentioned above where the construction cost is optimized and, in addition, the effectiveness in the main driving gears is improved with regard to the towing and toothing losses.

According to the invention said problem is solved by the features of claim 1. Advantages and other advantageous developments result from the sub-claims.

An inventive multiple gear transmission in planetary design is accordingly proposed which has one input shaft and one output shaft located in one housing. There are further provided three single-web planetary sets, six rotatable shafts and six shifting elements comprising clutches and brakes whose selective engagement by pairs produces different reduction ratios between input shaft and output shaft so that seven forward gears and two reverse gears can preferably be implemented.

According to this invention, in the multiple gear transmission is provided that the input results by one shaft directly connected with the sun gear of the first planetary set and that the output results via one shaft connected with the web of the second planetary set. It is further provided in the inventive multiple gear transmission that one other shaft be permanently connected with the sun gear of the second planetary set and the sun gear of the third planetary set, that one shaft permanently connects the web of the first planetary set with the ring gear of the third planetary set, that one shaft be permanently connected with the ring gear of the first planetary set and that one other shaft connects the web of the third planetary set with the ring gear of the second planetary set, the planetary sets being coupled with shafts and shifting elements.

The inventive development of the multiple gear transmission results in adequate ratios and considerable increase of the total spread of the multiple gear transmission whereby the driving comfort is improved and consumption significantly reduced.

The inventive multiple gear transmission is suitable for every motor vehicle, especially for passenger vehicles and for industrial motor vehicles such as trucks, autobuses, construction vehicles, rail vehicles, track-laying vehicles and the like.

Due to the small number of shifting elements, preferably three clutches and three brakes, the construction cost is considerably reduced with the inventive multiple gear transmission. It is advantageously possible with the inventive multiple gear transmission to start with a hydrodynamic converter, an external starting clutch, or also any other suitable external starting elements. It is also conceivable to make a starting operation possible with one starting element integrated in the transmission. One shifting element actuated to the first gear and to the reverse gear is preferably adequate.

With the inventive multiple gear transmission, a good efficiency further results in the main drive gears in relation to towing and toothing losses.

Besides, small torques exist in the shifting elements and in the planetary sets of the multiple gear transmission whereby the wear is advantageously reduced in the multiple gear transmission. The low torques also make a correspondingly small dimensioning possible whereby the needed installation space and the costs are reduced. In addition, there are also low rotational speeds in the shafts, the shifting elements and the planetary sets.

Besides, the inventive transmission is drafted so as to make possible an adaptability to different drive line designs both in power flow direction and with regard to space.

The invention is herebelow explained in detail by way of example with reference to the drawing. In the drawing:

FIG. 1 is a diagrammatic view of a first embodiment of an inventive multiple gear transmission;

FIG. 2 is a diagrammatic view of a second embodiment of an inventive multiple gear transmission; and

FIG. 3 is a wiring diagram for the inventive multiple gear transmission according to FIGS. 1 and 2.

In FIG. 1 is shown the inventive multiple gear transmission with one input shaft 1 (An) and one output shaft 2 (Ab) located in one housing. Three planetary sets P1, P2, P3 are provided which are preferably minus planetary sets.

As can be seen from FIGS. 1 to 3, only six shifting elements are provided. In the first embodiment according to FIG. 1, three brakes 03, 04 and 05 and three clutches 14, 16 and 56 are provided. In the second embodiment according to FIG. 2, the brakes 03, 04 and 05, the same as clutches 45, 16 and 56, are provided.

A selective shifting of seven forward gears and two reverse gears can be implemented by the shifting elements provided in the embodiments. The inventive multiple gear transmission has a total of six rotatable shafts, namely, shafts 1, 2, 3, 4, 5 and 6.

In the two embodiments shown of the multiple gear transmission, it is inventively provided that the input results by the shaft 1 which is directly connected with the sun gear of the first planetary set P1 and that the output results via the shaft 2 connected with the web of the second planetary set P2. In addition, the shaft 3 is permanently connected with the sun gear of the second planetary set P2 and the sun gear of the third planetary set P3 and the shaft 4 permanently connects the web of the first planetary set P1 with the ring gear of the third planetary set P3. The shaft 5 is besides permanently connected with the ring gear of the first planetary set P1. The shaft 6 permanently connects the web of the third planetary set P3 with the ring gear of the second planetary set P2.

In both embodiments according to FIGS. 1 and 2, respectively, to the housing can be attached the shaft 3 by the brake 03, the shaft 4 by the brake 04 and the shaft 5 by the brake 05. The clutch 16 detachably interconnects the shaft 1 and the shaft 6. The shaft 5 and the shaft 6 are detachably interconnected via the clutch 56.

In the first embodiment of the inventive multiple gear transmission according to FIG. 1, the shaft 1 and the shaft 4 are additionally detachably interconnected by the clutch 14. Differing therefrom, in the second embodiment according to FIG. 2, the shaft 4 and the shaft 5 are detachably interconnected via the clutch 45.

In FIG. 3 is shown a wiring diagram of the inventive multiple gear transmission which applies to both embodiments. A difference is that for the first embodiment in FIG. 1, the clutch 14 and for the second embodiment according to FIG. 2 the clutch 45 are respectively provided next to the other clutches 16 and 56.

A respective ratios i of the individual gear steps and a ratio ranges φ to be determined therefrom can be deduced by way of example from the wire diagram of the inventive multiple gear transmission shown in FIG. 3. From the wiring diagram can also be deduced that double shifts are prevented in sequential shifting mode, since two adjacent gear steps respectively, use in common one shifting element. It can further be deduced from the wiring diagram of FIG. 3 that in every desired shift between the first and the fourth gear, the same as between the fourth and the seventh gear, only one shifting element has to be additionally actuated.

In shifting operations between the first and the fourth gears, th brake 03 is activated each time, there being additionally activated in the first gear the brake 05, in the second gear the clutch 56, in the third gear the clutch 14 in the first embodiment or the clutch 45 in the second embodiment and the clutch 16 in the fourth gear.

During shifting operations between the fourth and the seventh gear, the clutch 16 is activated each time and additionally activated are in the fifth gear the clutch 14 in the first embodiment or the clutch 45 in the second embodiment, in the sixth gear the brake 05 and in the seventh gear the brake 04. In the first reverse gear, the brake 05 and the clutch 56 are activated as shifting elements, the brake 04 and the clutch 56 being activated in the second reverse gear.

It is possible, according to the invention, to provide additional free wheels on each adequate place of the multiple gear transmission, for example, between one shaft and the housing or in order to separate or also to connect one shaft.

In addition the inventive design makes situating input and output on the same side of the transmission possible or of the housing, preferably for transverse, forward, rear-longitudinal or four-wheel arrangements. One axle differential or one distributor differential can also be placed on the input side.

Within the scope of an advantageous development, the input shaft can be separated as needed from a prime mover by a coupling element, it being possible to use one hydrodynamic converter, one hydraulic clutch, one dry starting clutch, one wet starting clutch, one magnetic clutch, or one centrifugal clutch as a coupling element. It is also possible to situate one such starting element in power flow direction behind the transmission, the input shaft being, in this case, permanently connected with the crankshaft of the engine. According to the invention, it is also possible to start by means of one shifting element of the transmission. As shifting element can preferably be used the brake 03, the brake 04, or the brake 05.

The inventive multiple gear transmission also makes one torsional vibration damper possible to place between engine and transmission.

Within the scope of another embodiment of the invention (not shown), it is possible to situate upon each shaft, preferably upon the input shaft 1 or the output shaft 2, one wear-free brake such as a hydraulic, electric retarder, or the like, which is of special importance for use in industrial vehicles. For driving additional aggregates, it is further possible upon each shaft to provide one power take off, preferably upon the input shaft 1 or the output shaft 2.

The shifting elements used can be designed as powershift clutches or brakes. There can be specially used force-locking clutches or brakes such as multi-disc clutches, band brakes and/or cone clutches. As shifting elements can also be used form-locking brakes and/or clutches such as synchronizer or dog clutches.

One other advantage of the multiple gear transmission introduced here consists in that an electric machine can be mounted on each shaft as generator and/or as additional prime mover.

Reference numerals

-   -   1 shaft p1 planetary set     -   2 shaft p2 planetary set     -   3 shaft p3 planetary set     -   4 shaft An input     -   5 shaft Ab output     -   6 shaft i ratio     -   03 brake φ ratio range     -   04 brake     -   05 brake     -   14 clutch     -   16 clutch     -   45 clutch     -   56 clutch 

1-19. (canceled)
 20. A multiple gear transmission in planetary design, especially an automatic transmission for a motor vehicle, comprising an input shaft (1) and an output shaft (2) located in one housing, three single-web planetary sets (P1, P2, P3), six rotatable shafts (1, 2, 3, 4, 5, 6) and six shifting elements (03, 04, 05, 14, 16, 45, 56) including brakes and clutches, the selective engagement of which by pairs produces different reduction ratios between said input shaft (1) and said output shaft (2) so that seven forward gears and two reverse gears can be implemented, wherein the input results by the input shaft (1) directly connected with a sun gear of a first planetary set (P1), that the output results via the output shaft (2) connected with a web of the second planetary set (P2), that a third shaft (3) is permanently connected with a sun gear of the second planetary set (P2) and a sun gear of a third planetary set (P3), that a fourth shaft (4) permanently connects a web of the first planetary set (P1) with a ring gear of the third planetary set (P3), that a fifth shaft (5) is permanently connected with a ring gear of the first planetary set (P1) and that a sixth shaft (6) permanently connects a web of the third planetary set (P3) with a ring gear of the second planetary set (P2) wherein the third shaft (3) is attachable to the housing by a first brake (03), a fourth shaft (4) is attachable to the housing by a second brake (04), a fifth shaft (5) is attachable to the housing by a third brake (05), a first clutch (16) detachably interconnects the input shaft (1) and a sixth shaft (6), a second clutch (56) detachably interconnects the fifth shaft (5) and the sixth shaft (6) and either one of a third clutch (14) detachably interconnects the input shaft (1) and the fourth shaft (4) or one fourth clutch (45), the fourth shaft (4) and the fifth shaft (5).
 21. The multiple gear transmission according to claim 20, wherein three single-web planetary sets (P1, P2, P3) are designed as minus planetary sets.
 22. The multiple gear transmission according to claim 20, wherein additional free wheels can be inserted in every adequate place.
 23. The multiple gear transmission according to claim 22, wherein said free wheels are provided between the shaft and the housing.
 24. The multiple gear transmission according to claim 20, wherein input and output are provided on the same side of the housing.
 25. The multiple gear transmission according to claim 20, wherein one or more of an axle and one distributor differential is provided on one of the input side or the output side.
 26. The multiple gear transmission according to claim 20, wherein said input shaft (1) can be separated from a prime mover by a clutch element.
 27. The multiple gear transmission according to claim 26, wherein a one hydrodynamic converter, one hydraulic clutch, one dry starting clutch, one wet starting clutch, one magnetic clutch or one centrifugal clutch can be provided as a coupling element.
 28. The multiple gear transmission according to claim 20, wherein an external starting element, can be situated in a power flow direction behind the transmission, the input shaft (1) being fixedly connected with a crankshaft of the engine.
 29. The multiple gear transmission according to claim 20, wherein the starting results by means of a shifting element of the transmission, the input shaft (1) being permanently connected with a crankshaft of the engine.
 30. The multiple gear transmission according to claim 29, wherein the first brake (03), the second brake (04) or the third brake (05) can be used as a shifting element.
 31. The multiple gear transmission according to claim 20, wherein one torsional vibration damper can be placed between the engine and the transmission.
 32. The multiple gear transmission according to claim 20, wherein one wear-free brake can be situated upon each of the six rotatable shafts.
 33. The multiple gear transmission according to claim 20, wherein a power takeoff can be situated upon each of the six rotatable shafts for driving additional aggregates.
 34. The multiple gear transmission according to claim 33, wherein said power takeoff can be placed upon one of the input shaft (1) or the output shaft (2).
 35. The multiple gear transmission according to claim 20, wherein the shifting elements are designed as one of powershifting clutches or brakes.
 36. The multiple gear transmission according to claim 35, wherein one or more of multi-disc clutches, band brakes and cone clutches can be used.
 37. The multiple gear transmission according to claim 20, wherein one or more of form-locking brakes and clutches are provided as shifting elements.
 38. The multiple gear transmission according to claim 20, wherein an electric machine can be mounted upon each of the six rotatable shafts as one or more of a generator and an additional prime mover. 